Sleep problems play an important role in the onset and maintenance of many mental health problems, but the reason for this link is elusive. One of the remaining pieces of this link between lack of sleep and mental health problems could be related to deficits in brain regions that keep unwanted thoughts out of the mind, according to research from the University of East Anglia (UEA).
In a recent study published in the journal Proceedings of the National Academy of Sciences (PNAS), Dr. Marcus Harrington, professor at the UEA School of Psychology, and colleagues from the universities of York, Cambridge, Sussex and Queen’s University ( Canada), offer new insights into the cognitive and neural mechanisms underlying the connection between sleep and mental health. At the same time, they reveal that sleep deprivation can negatively affect our ability to control unwanted memories. These findings could support the development of new treatments and prevention strategies for mental health problems such as depression and anxiety.
Researchers conducted an experiment with 85 healthy young adults between the ages of 18 and 30, divided into two groups: one who stayed awake all night and another who enjoyed a restful night’s sleep in the sleep lab. Participants performed a task designed to measure their ability to suppress specific memories. Those who did not sleep showed greater difficulty in preventing unwanted thoughts from emerging in their minds.
However, during memory suppression, well-rested participants showed greater activation in the right dorsolateral prefrontal cortex (a brain region that controls thoughts, actions, and emotions) compared to those who stayed awake the entire day. evening. Rested participants also showed reduced activity in the hippocampus (a brain region involved in memory retrieval) during attempts to suppress unwanted memories.
Among participants who slept in the laboratory, those who spent more time in REM sleep were better able to activate the right dorsolateral prefrontal cortex during memory suppression, indicating a role for REM sleep in restoring prefrontal control mechanisms that they support the ability to prevent unwanted memories from entering conscious thought.
Thus, using functional magnetic resonance imaging (fMRI) neurological imaging, researchers managed to reveal for the first time that deficits in memory control after sleep deprivation are related to difficulties activating brain regions that support memory inhibition. memory recovery, such as the prefrontal cortex, and that nocturnal rejuvenation of these brain regions is associated with rapid eye movement (REM) sleep.
Explanation of the link between sleep problems and mental disorders
This study provides a possible explanation for why people with sleep disorders often experience intrusive thoughts and unwanted memories, common symptoms in conditions such as depression and post-traumatic stress disorder. Dr Harrington said: “Memories of unpleasant experiences can invade consciousness, often in response to reminders. While these intrusive memories are an occasional and momentary disturbance for most people, they can be recurring, vivid and disturbing for others. people suffering from mental health disorders such as depression, anxiety and post-traumatic stress disorder.
The UEA team suggests that improving sleep quality could be an effective strategy to strengthen the brain’s ability to control unwanted memories and therefore mitigate symptoms associated with various mental health conditions. “Given that memories play a central role in our affective perception of the external world, failures in memory control may go a long way to explaining the relationship between sleep loss and emotional dysregulation. A better understanding of the mechanisms that precipitate the emergence of intrusive memories is vital to improving emotional well-being and reducing the overall burden of mental illness.”
These findings underscore the importance of prioritizing sleep in our daily routine, not only for physical well-being, but also for maintaining optimal mental health. The study also opens new avenues to investigate how interventions targeting sleep could help in the treatment of disorders related to intrusive thoughts.
Dr Harrington said: “Taken together, our findings highlight the critical role of sleep in maintaining control of both our memories and our thoughts.”
Source: PNAS and University of East Anglia
